Feeling like you can't get enough air can be scary. This feeling is called shortness of breath. It also is called dyspnea. It might feel like your chest is tight. Or you have trouble breathing or can't breathe at all. Sometimes it may feel like you're suffocating.

Shortness of breath can be a sign of some medical conditions, including asthma, COPD and heart failure, as well as anxiety or panic attacks. The long-term lung effects of smoking may first be noticed as worsening shortness of breath.

Even people with healthy lungs may notice shortness of breath with stress or anxiety, very strenuous exercise, very hot or very cold weather, weight gain, and traveling to higher altitudes.

If you have shortness of breath that doesn't have a clear cause, especially if it comes on suddenly and is severe, see your doctor or other healthcare professional as soon as possible.